Whoa. The "Lost" writers weren't joking when they said the last bit of this season would be explosive. In one of the most emotionally powerful and tragic episodes of the season, Jack finally faces the possibility that it is his fate to remain on the island, and the Man in Black's plot becomes all the more apparent as the 815ers make a final run for it on Widmore's sub.

Spoilers herein.

First off, let's get the alt-timeline out of the way, as it was good but relatively inconsequential compared to the island plot.

"The Last Recruit" left us off with Jack performing surgery to save Locke after he was run down by Desmond. "The Candidate" reveals the surgery to have been a success--Jack has saved Locke's life, but out of concern for Locke's pre-existing spinal fracture, Jack asks Locke how it happened. Locke's not ready to talk about it, but Jack tells him he may be a candidate for an experimental procedure that may let him walk again. Locke refuses--understandable, really, after seeing him come to terms with it in "The Subsitute."

In a sort of odd change of pace, this is more of a dual-centric between Jack and Locke. Less because we see a lot of Locke, and more because through Jack's efforts to uncover Locke's past, it ends up focusing on both of them pretty much equally, in the alt, at least. Eventually, Jack tracks down Locke's father, Anthony Cooper, who, as we recall, is responsible for paralyzing Locke in the regular timeline. Things are much different now, however--Cooper's past as a con man may be the same, but he never got the opportunity to steal Locke's kidney and hurl him out of a window. Jack finds Cooper at a retirement home, in a wheelchair himself, and catatonic.

When Jack confronts Locke about it, Locke tearfully admits that he is responsible for Cooper's condition--after getting his private pilot's license, he accidentally crashed a plane with his father in it, paralyzing them both.

I think this is one of the best juxtapositions the show has had this season--Locke no longer has to struggle with his relationship with his father falling apart due to malice, but to dumb bad luck. And the fact that a plane crash crippled Locke instead of healing him is pretty brilliant as well.

So, that's a sweet little story, but the meat of "The Candidate" is in the island story. With Sawyer and company captured by Widmore, whose motives are becoming more and more suspect, Jack, Sayid and Smokey plan to bust them out and head for the plane. We get another badass Smokey massacre and Jack's pals are free, but as they approach the plane ready to take off, Flocke tells them that Widmore has wired the plane with explosives and that it would be safer to commandeer the submarine.

Jack, still determined to remain on the island to fulfill whatever his destiny may be, agrees to help them get on the submarine, but then he's done. But Sawyer isn't quite ready to trust Flocke, and after a vicious shoot-out with Widmore's people, everyone hops on the sub and Sawyer locks it up before Flocke can get in. Claire is accidentally left behind as well. As she runs for the sub, Flocke holds her back. He tells her she doesn't want to be on that sub.

Uh oh.

As Jack tends to a bullet wound Kate got in the shoot-out, he opens his backpack. He doesn't find a first-aid kit. Instead, he finds a bomb, the countdown reading four minutes. In mere moments, the entire situation becomes clear to Jack and company. Smokey never wanted on the sub. Richard, Jacob, Dogen--they were all right. Flocke doesn't want to help them leave the island, he just needs them all in one place so he can take them all out at once.

As the minutes count down, decisions have to be made, but this group isn't what it used to be. Jack isn't the leader anymore and he's willing to trust that the island or fate will save them. Sawyer doesn't trust anyone. Sayid is hardly himself. But they have to do something. Sayid looks at Jack. He tells him Desmond is still alive in a well on the island. He tells Jack, "It's going to be you." What is? Doesn't matter. Sayid lunges, grabbing the bomb and charging through the sub. It explodes, killing Sayid as water starts rushing in.

But that apparently wasn't enough tragedy--moments later, as Jack, Sawyer, Kate and Hurley swim from the sub to safety, Jin and Sun meet an underwater demise as well. Three major deaths in a row. Harsh.

This sequence is one of the most tense and powerful moments this season--credit has to go to Jack Bender, the show's go-to helmer for big moments like this.

Basically, this confirms at least one thing. Smokey is not a good guy. All bets are off on that one. Three episodes to go, and the sides are definitely chosen--it's everyone against the Man in Black. And what a deeply unfortunate set of circumstances to confirm his villainy.

Overall, the episode is rather unfocused--its attempts to be a centric for both Jack and Locke doesn't quite work and it's really lacking in strong character moments, but for the most part, this episode is nevertheless a real tour de force. More tragic than "Lost" has been since "Two for the Road" and powerfully acted and directed to boot, there's no denying the show is going out with a bang. The only real question left is how many more bodies are going to pile up before the final moments.

One final thing to note is the how effectively each character's arcs are coming to a close. Jack, no longer in any sort of strong leadership role, has given his life to the island and is suffering from the same lack of confidence from his friends that he gave Locke before his death. Sayid, finally faced with a true good or evil decision, sacrifices his life and proves without a doubt that he was a good man. Jin and Sun, finally reunited, die in each others' grasp. Say what you will about some of the rather questionable moments of fanservice this season, but as long as they keep churning out powerful stories like these, they can make as many tired references as they want.

Just three episodes to go, folks. Next week apparently takes a break from the current island storyline to give us another "Ab Aeterno"-esque tale about Jacob and Smokey. Also, take note that the former two hour finale has now been extended to 2.5 hours. Awesome.